Secondary clock



Oct. 4, 1938. B CHAPMAN 2,131,915

SECONDARY CLOCK Filed May 28, 1936 I l l ATTORNEY Patented Oct. 4, 1938 UNITED STATES PATENT OFFICE ternational Business Machin es Corporation,

New York, N. Y., a corporation of New York Application May 28, 1936, Serial No. 82,221

ZCIaims.

'I'his invention relates to electric clocks and more particularly to electric clocks of the impulse type which are operated by electric impulses initiated at predetermined timed intervals under control of a master clock.

It is the object of this invention to provide a new and improved construction of such a clock which will be simple and rugged, with a minimum number of parts and will be comparatively inexpensive to manufacture.

Other objects and advantages of this invention will be apparent from the specification and the accompanying drawing which shows one embodiment of this invention and where in similar l5 reference numerals indicate similar parts and wherein in the drawing:-

Fig. 1 shows a rear elevation of the clock movement.

Fig. 2 shows a detail of one of the parts of the clock mechanism.

A mounting plate 5 is provided on which pole pieces 6 and E of a magnet 1 are mounted by means of screws 8 and 8'. The pole pieces are spaced outwardly from the mounting plate by tubular spacers (not shown) between the plate and the pole pieces. A bracket 8 is rigidly secured to said pole pieces by said screws and provides a bearing for a shaft I0 which extends through the mounting plate 5 and is journaled therein. 'I'he shaft I0 is the minute hand shaft of the mechanism and has mounted thereon a minute hand I I and through the usual reduction gears I2 operates the hour hand I3.

Fixed to the shaft Ill is a ratchet wheel I4 which, in the preferred embodiment, carries 60 teeth whereby the rotation of the ratchet wheel rotates an amount equivalent to one tooth each minute causes it to make one revolution per hour. Cooperating with the ratchet wheel Il is an actuating pawl I5 pivotally mounted on the arm I6 which is an integral part of the member Il, (Fig. 2). The member I1 is loosely mounted on the shaft III and is mounted immediately adjacent to the armature I8 also pivotally mounted on the shaft II). 'I'he armature I8 oscillates between the pole pieces 6 and 8'. The member I1 is provided with an arm I8 having lugs 20 and 2I formed over to grip the armature I8 and having an arm 22 extending in the opposite direction bearing against the side of the armature to prevent a twisting action about its bearing. The lug 2I has attached thereto a spring 23 which is anchored to a set screw on an adjustable collar 24 mounted on a stud which is fixed in the base plate. By turning the collar on the pivot and setting it with a set screw an adjustment in the tension of the spring 23 is obtained. A limit stop 25 is mounted on an arm 26 which is adjustably mounted on the mounting plate 5 by screws 2l, the arm 26 having holes slightly larg r than the screw shanks to permit slight adjustment. Arm 28 of the member I1 has a formed-over portion which cooperates with said limit stop to limit the clockwise movement as viewed in Fig. 1 of the member Il when the magnet is energized and said limit stop cooperates with the pawl I5 in the counterclockwise movement of the member Il upon deenergization of the magnet.

A retaining pawl 29 is pivotally mounted to a stud and cooperates with ratchet wheel I4 to prevent retrograde movement. A pair of contacts 30 is mounted on the base plate 5 and insulated therefrom and is operated by means of an insulated disk 3I mounted on an arm 32 which is pivotally mounted to a stud 35 in the base plate 5 and which has integral therewith an arm 33 which cooperates with a pin 3l mounted ln the ratchet wheel I4. Upon each revolution of the ratchet wheel Il the pin 34 strikes the arm 33 moving said arm, and the arm 32, clockwise, thereby opening the upper and closing the lower of the pair of contacts 30. When the pin has passed by the arm, the spring action of the midl dle blade of the contacts rotates the arm counterclockwise to close the upper and open the lower of the pair of contacts.

Normally when the magnet 1 is deenergized, the armature I8 is tilted slightly counterclockwise so that the pawl I5 rests against the limit stop 25 due to the tension of the spring 23. When an electric impulse is received by said magnet, the armature I8 is moved clockwise to be pulled into the magnetic field between the pole pieces 6 and 6 thus rotating the member Il clockwise and moving the pawl I5 to pick up the next adjacent tooth to the right as viewed in Figure 1 and upon the next deenergization, the arm I1 and the armature attached thereto move counterclockwise carrying the ratchet wheel Il a distance equivalent to one tooth and thereby moving the minute hand of the clock a distance to indicate an advance of one minute.

While the fundamental novel features of the invention as applied to a single modification have been shown and described and pointed out, it' will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. I intend to be limited therefore only as indicated by the scope of the following claims.

What is claimed is:

1. A secondary clock including a front supporting plate, a rear supporting bracket and a minute shaft journaled therein, a ratchet wheel afxed to said shaft, a, projecting member mounted on said ratchet wheel and synchronizing control means controlled by the rotation oi' said projection through its orbit, said synchronizing control means comprising contacts mounted on:

said front supporting plate, and a member pivotally mounted on said plate and having one arm cooperating with said contacts to control the position thereof and another arm extending into the orbit oi said projecting member and operable thereby.

2. An electric clock mechanism including a ratchet wheel and a pawl foradvancing said wheel, a pawl carrier for said pawl pivotally mounted on an axis common to said ratchet wheel, a driving magnet, an amature associated therewith disposed lengthwise of said magnet and oscillatable about said axis, said pawl carrier having a U-shaped extension integral therewith to releasably engage a portion oi.' said amature whereby the oscillation of said armature will cause said pawl carrier to oscillate to advance said ratchet wheel.

BERT CHAPMAN. 

